| Abstract: | 1. The rate constants for NADH binding and dissociation for carboxymethylated alcohol dehydrogenase have been determined and compared to those for the native enzyme. 2. Steady-state and transient kinetic experiments have shown that the hydrogen transfer step is rate-determining for oxidation of ethanol by carboxymethylated alcohol dehydrogenase. The rate constant of 0.19 s-1 is considerably slower than that for the native enzyme. 3. The steady-state parameter, V/E], was obtained for each of a series of alcohols and correlated with the Taft sigma parameter. The linear relationship obtained indicates that the same step, hydrogen transfer, is rate-determining for all the alcohols. The sigma value obtained is the same as for the native enzyme; the implications of this for the mechanism of hydrogen transfer are discussed. |
